vmclient: Spawn child virtmgr and connect to it

Instead of connecting to the global virtualizationservice, make
vmclient::connect() spawn a child virtmgr process and connect to it via
RpcBinder.

Bug: 245727626
Test: atest -p packages/modules/Virtualization:avf-presubmit
Change-Id: I456a151071a5f0d8448b11b89d88c1c2892f911f
diff --git a/vmclient/Android.bp b/vmclient/Android.bp
index 88b0c9a..0a2e692 100644
--- a/vmclient/Android.bp
+++ b/vmclient/Android.bp
@@ -11,8 +11,11 @@
         "android.system.virtualizationcommon-rust",
         "android.system.virtualizationservice-rust",
         "libbinder_rs",
+        "libcommand_fds",
         "liblog_rust",
+        "libnix",
         "librpcbinder_rs",
+        "libshared_child",
         "libthiserror",
     ],
     shared_libs: [